Audio problem: When Ed picks up the hooker and they are driving and talking it is a pretty quiet conversation considering that Ed busted out one of the windows to get Rebecca DeMourney's cell phone away from her. There should be some noise from the wind in the broken window. (00:09:50 - 00:12:30)
Audio problem: When Paris goes to get her money from the hotel room and runs into Ed, in one shot Paris is talking, then it changes to Ed's face and Paris is still talking, but her mouth isn't moving. (00:45:55)
Answer: The actual, "real-life" killings happened before the events shown in the movie and are shown briefly in a flashback. The authorities knew that Malcolm had done it while believing to be one of his alternate personalities, but did not know which one, and had to be convinced that the killer personality was dead before changing his sentence to life imprisonment. Meanwhile, the killings we see in the motel during the movie, are Malcolm killing off his other personas, leaving in fact only - the killer.
Twotall